Are All Males Liars And Cheaters? Yes -- If They're
Crayfish!

Intimidation and threats are common throughout society, whether it's in the
school playground, sporting arena or boardroom. Threatening behaviour is equally
widespread among non-human animals.

Individuals signal their superior strength to competitors to obtain food,
resolve territorial disputes and acquire mates. Current theory insists that
signals of strength should be honest. Surprisingly researchers have found that
dishonest signals are used routinely during dominance disputes by male
Australian crayfish. This work was presented by Dr Robbie Wilson (University of
Queensland) on 2nd April at the Society for Experimental Biology's Annual
Meeting in Glasgow.

Crayfish are a naturally aggressive species and will squabble over almost
anything! Male crayfish possess enlarged front claws that they use to intimidate
and fight with their competitors. An international team of researchers, led by
Robbie Wilson from the University of Queensland, wanted to understand
determinants of social dominance in these aggressive animals.

The scientists measured the size and strength of claws of both male and
female crayfish, and then monitored how they performed in competitive bouts.
They found crayfish use claw size to determine the winners of the most
aggressive disputes. For female crayfish the size of the claw was an honest
indication of how strong they were. However, claw size of males was not a good
indicator of their strength. Males were routinely bluffing their opponents with
weak claws to achieve dominance. They used claws more for intimidation than
actual strength.

"Male crayfish lie and cheat their way to the top, whilst females appear to
be honest displayers of their own strength", Robbie Wilson said. "This is
important work showing that dishonesty is commonly used by animals during
fights", said Wilson. "We already knew humans often use dishonesty during
disputes, but our results suggest cheating may play a more important role in
animal communication than previously imagined."